In an image forming apparatus, such as a laser printer or a copying machine, a process cartridge which is attachable to and detachable from a main body (hereinafter, referred to as an “apparatus main body”) of the image forming apparatus is provided.
The process cartridge is a member which forms contents to be expressed by letters or figures and transfers the contents to a recording medium, such as a paper sheet. More specifically, in the process cartridge, the photoreceptor drum is included, and the contents to be transferred are formed onto the photoreceptor drum. In addition, in the process cartridge, various other means for forming the contents to be transferred onto the photoreceptor drum are also disposed. Examples of the means include a developing roller unit, a charging roller unit, and means for performing cleaning.
The process cartridge attaches and detaches the same process cartridge to and from the apparatus main body for maintenance, or disengages an old process cartridge from the apparatus main body and mounts a new process cartridge on the apparatus main body. Attaching and detaching the process cartridge in this manner can be performed by users of the image forming apparatus themselves, and from this point of view, it is desirable to perform attaching and detaching as easily as possible.
Meanwhile, the photoreceptor drum included in the process cartridge is configured to be engaged with a driving shaft of the apparatus main body directly or via another member, and accordingly, to receive a rotating force from the driving shaft and to rotate. Therefore, in order to attach and detach the process cartridge to and from the apparatus main body, it is necessary to release (disengage) the engagement between the driving shaft of the apparatus main body and the photoreceptor drum every time attaching and detaching occur, and to mount the process cartridge again.
Here, if it is possible to move the photoreceptor drum (process cartridge) in the shaft line direction of the driving shaft of the apparatus main body, and to attach and detach the photoreceptor drum to and from the driving shaft, the configuration of the apparatus can be relatively simple. However, from the viewpoint of reducing the image forming apparatus in size or ensuring an attachment and detachment space of the process cartridge, it is preferable to disengage the process cartridge from the apparatus main body to be pulled out in the direction which is different from the shaft line direction of the driving shaft, and to mount the process cartridge on the apparatus main body to be pushed in a direction opposite to the direction.
In PTL 1, a configuration for attaching and detaching a process cartridge in a direction different from the shaft line direction of the driving shaft of the apparatus main body, is disclosed. Specifically, a coupling member described in PTL 1 is swingably attached to a drum flange (bearing member) by providing a spherical portion. Therefore, a part (rotating force receiving member) which is provided in the coupling member and is engaged with the driving shaft of the apparatus main body can swing around the spherical portion and change an angle with respect to the shaft line of the photoreceptor drum, and it is easy to mount and disengage the driving shaft of the apparatus main body and the photoreceptor drum to and from each other.
In addition, in the invention described in NPL 1, in a structure in which a swinging shaft member is linked to a bearing member, a groove for introducing a rotating force transmission pin provided in the shaft member into the bearing member is provided on an inner circumferential side of the bearing member. The groove is formed so as to extend in a rotation direction, and it becomes easy to attach the rotating force transmission pin to the bearing member by the groove.